Menu中弹出Dialog示例

main.xml如下:

<RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
     >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="请点击菜单键" />

</RelativeLayout>

dialog.xml如下:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:textSize="20sp"
        android:textColor="@android:color/white"
        android:text="this is a dialog" 
     />
</RelativeLayout>

main.xml如下:

<menu xmlns:android="http://schemas.android.com/apk/res/android" >


    <item
        android:id="@+id/exit"
        android:icon="@drawable/ic_launcher"
        android:title="退出"/>
    <item
        android:id="@+id/aboutme"
        android:title="About me"/>

</menu>

MainActivity如下:

package com.wy;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.content.DialogInterface;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater menuInflater = this.getMenuInflater();
menuInflater.inflate(R.menu.main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.exit) {
finish();
}
if(item.getItemId() == R.id.aboutme) {
AlertDialog.Builder builder = new Builder(this);
LayoutInflater inflater=getLayoutInflater();
View xmlView=inflater.inflate(R.layout.dialog, null);
builder.setView(xmlView);
AlertDialog dialog=builder.create();
dialog.setIcon(R.drawable.ic_launcher);
dialog.setTitle("welcome");
dialog.setButton("OK",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface clickedDialog, int arg1) {
clickedDialog.cancel();
}
});
dialog.show();



}
return super.onOptionsItemSelected(item);
}

}